Thermostatic valve structure for hydraulic shock absorbers



June 25, 1935. x R PEQ 2,005,751 I THERMOSTATIC VALVE STRUCTURE FORHYDRAULIC SHOCK ABSORBERS Original Filed April 29, 1933 2 Sheets-Sheet 1.ZTFEZWZUF June 25, 1935. R PEQ 2,005,751

VALVE STRUCTURE FOR HYDRAULIC SHOCK ABSORBERS Original Filed April 29,1933 2 Sheets-Shed; 2

Patented June 25, 1935 UNITED STATES THERMOSTATIC VALVE STRUCTURE FOR.HYDRAULIC SHOCK ABSORBERS Ralph F. Peo, Buffalo, N. assignor to HoudeEngineering Corporation, Bufialo, N. Y., a corporation of New YorkOriginal application April 29, l9 33, serial No.

Divided and this application Novem:

ber 18, 1933, Serial No. 698,621v

8 Claims. (01. 188100) This invention relates to thermostatic valvestructure adapted particularly for use in hydraulic shock absorbers forcontrolling the bypassage of resistance fluid from one sideof the 5piston structure to the other during operation of the shock absorber fordetermining shock absorbing resistance. This application is a divisionof the application of Ralph F. Peo, Serial No. 668,532, filed April 29,1933, in which application my improved valve structure is fullydisclosed but not claimed per se. i

An important object of the invention is to provide simple, moreeconomically manufactured and assembled, and more efficient and durablel5-- valve structure, which may be readily adjusted and set manuallyfrom the exterior ofa shock absorber and which is then thermostaticallyadjusted for control of the bypassage resistance to fluid flow inaccordance with variations in temperature of the resistance fluid.

A further object is to provide valve, structure for hydraulic shockabsorbers comprising two concentric rotary valve members having portscooperable for control of the fluid flow in a shock absorber, with theouter member manually adjustable from the exterior of the shock absorberand the inner member thermostatically adjusted.

Another object is to provide a valve structure which may be readilyinserted within the piston ment will then serve as a housing and supportfor the valve structure.

Still a further object is to provide a housing or container into whichthe inner valve member and the thermostat element of the 'valvestructure are assembled before association of the inner valve memberwith the outer valve member, which housing will hold in alignment andprotect the thermostat element which is preferably in the form of aspiral coil formed from a strip of bimetal whose metal layers are ofmaterial of different expansion coefiicients.

The above enumerated and'other' features of the invention are shownincorporated in the structure disclosed on the drawings, in whichdrawings Figure 1 is a verticalsection through the improved valvestructure and a hydraulic shock absorber to which it is applied for thepurpose of illustrating its operation, thesection being on plane II ofFigure 2; v

Figure 2 is a section 'on plane II--II of Figure 1;

Figure 3 is a section on plane III-III of Fig- 555 ure 1;

element of a shock absorber which piston e1e- Figure 4 is an inner endview of the valve structure housing showing the arrangement of thethermostat elementenclosing housing.

I have shown my improved valve structure in service in a well-known typeof hydraulic shock 5 absorber for controlling the flow of the hydraulicresistance .fluid. Briefly describing the shock absorber, it'comprisesthe supporting base lllhaving the cylindrical flange or wall Hextend-- ing therefrom with an outer wall I72 received in 10 the end ofthe cylindrical wall and held by the annular nut 13. The base with thecylindrical wall andthe end wall define a cylindrical space into whichfits the annular wall or ring Hi from which diametrically oppositepartition lugs 15 and I5 extend inwardly, this ring structure beingsecured by pins l6 extending through the lugs and into the base l0. 1

i A piston structure comprises the cylindrical hub l1 and piston vanes18 and 18' extending 20 therefrom at, opposite sides, the driving shaft19 of the piston structure extending from the huh I! through the bearingflange v2i! on the outer wall 12, the end of the shaft having securedthereto a lever 2| usually connected with the vehicle axle while theshock absorber body is connected at its base to the vehicle chassis. Theend surfaces of the vanes l8.and l8 engage the cylindrical inner surfaceof the ring 14' while the hub engages the inner'surfacesoi the partitionlugs l5 and [5, the piston structure'together with the partition lugsdividing the space within the ring into high pressure chambers 22: and22' and low pressure chambers 23 and 23..

Each of the piston vanes has a passage 24 therethrough providing a seat25 .for a check valve 25, such as a ball,the valves being arranged sothat the resistance fluid may flow from the low pressure chambers to thehigh pressure chambers during low pressure movement of'the pistonstructure, as when the vehicle chassis and axle move toward each other,but so that the valves-will close the bypassage against flow from thehigh pressure to the low pressure chambers during the high pressure orrebound movement of the vehicle, as when the chassis and axle areseparated by the vehicle spring recoil.

A separate more restricted pass is provided for flow of fluid from thehigh pressure to the low pressure chambers and this pass is also available for flow from the low pressure to the high pressure chambers inaddition to the flow through the bypassageways .24.. Provision is madeto control the high pressure flow in accordance with changeintemperature andviscosity the cylindrical chamber 28 which is connectedby the ducts 29 and 29' with the high pressure cham bers 22 and 22,these ducts extending "radially through the piston hub ll. Within thevalve chamber 28 is the outer valve member or frame 30 which iscylindrical and has the cylindrical bore 3| for receiving andseating-the inner valve member 32. The outer valve member 30 has thecircumferentially extending channel 33 in its Outer side forming aconnection between the innerend of the ducts 29 and 29, and the member30 has the port 34 therethrough communicating with the channel, the portshown being a circumferentially extending slot. The inner valve member'32 has a port 35,- shown as a circumferentially extending slot' forcooperating with the ,port 34 to control the fluidfiow. .The inner valvemember 32. is shown to be of tubular construction, forming a passagecommunicating with the p'ort 35 and included in the bypass circuit.

In the inner end of the piston structure hub I1 is the cylindricalpocket 36 which is concen trio "with the valve chamber 28.

ture for controlling the valve operation. The structure comprises acylindricalcup 31 which 2 may readily be formed of sheet metal, the cupbeing of such outer diameter as to frictionally'fitinto the pocket 36.Within the cup is the spiral thermostat coil 38 formed from a strip ofbimetal whose metal layers are of material of different expansioncoefflcients. The outer end 7 39 of the coil is'anchored tolthe cup, theend cup bottom, the chamber, 42, and

being deflected to extend radially into a slot 40 formedin a cylindricalwall of the cup. The cup is inserted in the pocket 36' with its bottomside out'so as to form a closure for the pocket. The cup receives theouter end of the tubular inner valve member 32. and in its bottom hasthe opening 4| registering with the bore of the valve member. The depthor axial width of the cup is less than the depth of the pocket 36 sothat after insertion of'the cup in the pocket there will 'remain'ashallow space or chamber 42 between the cup bottom and the base l0 7which base or chamber is connected by "ports' 43 and 43 with the lowpressure chamber 23 and 23 .respectively, the. bypassage from the highpressure chambers to the low pressure, chambers thusincluding theducts-29 and-29', the-channel 33', the valve ports 34 and 35,. the boreof. valve 32, theopening 4| through the the ports 43 and 43'.

The inner end 44 of the thermostat coil is deflected radially and isreceived in the longi-.. tudinal slot'45 in the inner .valve member 32so that. during winding and. unwinding movement of thecoil in responseto temperature change, the'inner valve member will be rotated foradjustment of its port 35 relative to, the. port 34in the outer valvemember.

The outer valve member 30 has a stem 46 extending axially therefrom andthrough the bore 21 in the housing. 20, the outer end of the This pocketserves to receive and house the thermostat strucstem being threaded forthe reception of a nut 41, the outer end of the valve member seatingagainst the annular shoulder 48. By loosening the nut 41, the stem 46may be turned for r0- tary movement of the outer valve member 30 andsetting of its port 34 relative to the'inner valve port 35. Theouter endof the stem may absorber resistance under normal temperature.

This setting'will be maintained if the temperature does not change. Ifthe shock absorber and the fluid should become heated and thefluidbecome less viscous, the thermostat coil will re-} spond to theincreased temperature and will automatically rotate the inner valvemember for less overlap of its port 35 with the port 34 of the outervalvepmember so that the flow or shock absorber resistance will remainthe same as that under normal temperature conditions. If y thetemperature should become r'educed below normal and thefluid become moreviscousrthe.

thermostat coil will respond to adjust the inner valve member forgreater port overlap-l to compensate for increase in viscosity and toretain.

the shock absorber resistance normal.

During the rebound stroke of the shock absorber, that is, when thevehicle spring tends to rapidly recoil. to. move the vehicle body awayfrom the axle, th e piston structure will rotate incounter-clockwisedirection (Figure 2 during which rotation thebypassages 24 will be held closed by the ball valves so thatthe onlyescape of fluid from the high pressure chambers to the low pressurechambers will be through the restricted passage. provided by theoverlapping ports 34 and 35, the flow being from the high pressurechambers 22 and 22' 29-49, through the channel 33 and-then through thevalve ports and the inner valve member to the chamberf42 and from therethrough the ports 43 and 43 to the lowpressure chambers.-

During theso-called bump stroke of the piston when the axle andlv'ehicle body come together, the piston structure will rotate'inclockwise direction (Figure 2), and the greater part of the fluid fiowfrom the low pressure chambers to the high pressure chamberswillbethrough the bypassages 24, the remainingv flow beingthrough thepassage controlled by the valve ports 34and35.. j .71 n

By providing a cylindrical pocket 36 of comparatively large diameter, alarge spiral thermostat coil having many turns will be accommodatedwhich will be very sensitive to temperature changes and powerful toaccurately adjust the bypassage resistance in accordance withtemperature and viscosity changes. Furthermore, the thermostat coil willhavea comparatively large range of angular adjustment of the inner valvemember. The container cup for the coil will protect the coil againstinjury before assembly in the pocket 36 and after assembly the coilwillbe entirely housed and protected against injury and to the ducts'winding movement of the coil so that the turning resistance of the valvewill be reduced to a minimum.

I have shown a practical and eflicient embodiment and application of thefeatures of my invention, but I do not desire to be limited to the exactconstruction and arrangement shown and described as changes andmodifications may be made without departing from the scope of theinvention as outlined in the accompanying claims.

I claim as follows: i v

1. A valve structure for hydraulic shock absorbers comprising a housinghaving a bypass therethrough for the flow of the resistance fluid of ashock absorber, said housing having an axial bore intersecting saidbypass, a rotary valve seated in said bore and having a port, said borebeing enlarged at one end to form a cylindrical pocket, and a spiralthermostat element in said pocket connected to rotate said valve forsetting of its port in said bypass in accordance with change intemperature of the resistance fluid flowing through said bypass.

2. A valve structure for controlling the flow of resistance fluid in ahydraulic shock absorber, comprising a housing having a boretherethrough, a resistance fluid by-pass intersecting said bore, acylindrical outer valve member within said bore having a portcommunicating with said bypass, an inner valve member seated in saidouter valve member and having a port for cooperating with the port ofthe outer member to control the flow through said bypass, a stemextending from said outer valve member and being manually operable forrotation of said outer valve member for relative setting of said ports,the inner end'of said bore being enlarged to form a pocket, and athermostat coil in said pocket connected to rotate said inner valvemember for setting of said ports in accordance with change in thetemperature of the resistance fluid. I

3. A valve structure for controlling the flow of resistance fluid in ahydraulic shock absorber comprising a housing having a boretherethrough, a bypass through said housing intersecting said bore, acylindrical outer valve member within said here having a portcommunicating with said bypass, an inner valve member seated in saidouter valve member and having av port for cooperating with the port ofthe outer member to control the flow of resistance fluid through saidbypass, a stem extending from said outer valve member through said boreand being manually operable for rotation of said outer valve member forrelative setting of said ports, the inner end of said bore beingenlarged to form a pocket, a cup in said pocket receiving the outer endof said inner valve member, and a thermostat coil in said cup connectedat one end to said cup and connected at its other end with said innervalve member for rotating said inner valve member for setting of saidports for adjustment of the bypassage flow in accordance with change intemperature of the resistance fluid.

4. A valve structure for controlling the flow of resistance fluid in ahydraulic shock absorber comprising a housing having a passage for theflow of resistance fluid, a valve journalled in said housing and havinga port for controlling said passage, said housing having a cylindricalpocket concentric with said valve, a cylindrical cup seated in saidpocket with its bottom forming a closure therefor, and a thermostat coilin said cup connected with said valve for automatic adjustment thereofin accordance with change in temperature of the resistance fluid.

5. A fluid flow controlling valve structure com 7 prising a housinghaving a cylindrical pocket and a cylindrical valve chamber concentricwith said pocket, an inner rotary valve member having a boretherethrough, a fluid flow passageway through said housing includingsaid valve bore, a

spiral thermostat element in said pocket sur rounding the outer end ofsaid inner valve member and secured at one end thereto and at its otherend to said housing, the inner end of said valve extending into saidvalve chamber, an outer valve member in said valve chamber surroundingand journalling the inner end of said inner valve member, said outer andinner valve members having ports registering with'said passageway, meansfor manually setting said outer valve member for setting of said ports,said thermostat element responding to change in temperature toautomatically rotate said inner valve member for setting of said portsin accordance with change of temperature of fluid going through saidpassageway.

6. A valve structure for controlling the flow of resistance fluid in ahydraulic shock absorber and comprising a housing having a longitudinalbore therethrough and a fluid passage connecting said bore with theexterior of said housing, a valve structure in said bore comprisingrelatively movable valve members, said valve members having portsarranged for inclusion in said fluid passage and for varying overlap forcontrolling the fluid flow, a thermostat element confined in the innerend of said bore and connected with one of said valve members forautomatically effecting movement thereof for adjustment of said ports,and means extending through the outer end of said bore and operable fromthe exterior thereof for manually moving the other valve member foradjustment of said ports. a

'7. A valve structure for controlling the flow of resistance fluid in ahydraulic shock absorber and comprising a housing having a. longitudinalbore providing a valve chamber intermediate its ends and a thermostatchamber at its inner end, said housing having a laterally extendingfluid passage connecting said valve chamber with the exterior of thehousing, a valve structure in said valve chamber comprising outer andinner valve members having ports and arranged for relative rotation forvarying overlap of said ports, a thermostat coil in said thermostatchamber connected with said inner valve member for rotation thereof foradjustment of said port, means in the outer end of said bore wherebysaid outer valve member may be manually rotated for setting of saidports, said inner valve member having a bore communicating with theexterior of said housing at the inner end thereof, said ports beinginterposed between said valve bore and said lateral passage.

8. A valve structure for controlling 'the flow of resistance fluid in ahydraulic shock absorber RALPH F. PEO.

